TrueNAS has renamed its upcoming release from TrueNAS 26 to TrueNAS 27, starting with the RC.1 released today. The change does not affect the release schedule, with TrueNAS 27.0 still planned for early December 2026.
The new naming reflects TrueNAS’s move to one major release per year. Instead of the previous year-and-month format, such as 25.10 or 25.04, major versions will now use the year in which most users are expected to deploy them. Point releases will then follow sequentially, beginning with TrueNAS 27.0.
The name change comes alongside several additions in RC.1. TrueNAS 27 is based on OpenZFS 2.4 and Linux kernel 6.18 and introduces TrueSearch and WebShare, Fusion Pools 2.0, stateful SMB failover for Enterprise HA systems, and an early-access native S3 interface.
TrueSearch and WebShare
TrueSearch adds server-side indexing for file names, metadata, and file contents stored on TrueNAS. On macOS, Spotlight Search can also be enabled for SMB shares, allowing Finder to search indexed NAS content without having the client scan the share over the network.
WebShare provides browser access to the same stored data from desktops, tablets, and phones while retaining existing ACLs and permissions. Users can browse files and snapshots, preview media, and share or collect files through the browser. Both TrueSearch and WebShare require TrueNAS Connect, and encrypted datasets are not indexed.
Fusion Pools 2.0 and Live Dataset Tiering
Fusion Pools 2.0 gives TrueNAS more flexibility in how SSD-based special vdevs work alongside hard-drive storage. In TrueNAS 27, special vdevs can now use RAIDZ instead of being limited to mirrored layouts. They can also be used in the ZFS log device chain for synchronous writes when there is no dedicated log device in the system or the dedicated device fails; a dedicated log device still takes priority when present.
TrueNAS Enterprise 27 RC.1 also adds Live Dataset Tiering. This allows data to move between flash and capacity storage while the dataset stays online and available to clients, making it easier to mix SSDs and hard drives without taking data offline during the move.
Stateful SMB Failover
TrueNAS Enterprise HA systems gain stateful SMB failover in this release. Previously, a controller failover could drop an active SMB session, forcing a client to reconnect and potentially interrupting a large file transfer.
With stateful failover enabled, SMB session state is maintained between controllers. Existing sessions can continue after a controller transition without requiring users to authenticate again, and active transfers can resume from their existing position. The feature is enabled through the SMB service settings on supported TrueNAS Enterprise HA systems.
OpenZFS 2.4 and Linux 6.18
The move to OpenZFS 2.4 brings changes to deduplication, encryption, write allocation, quotas, and pool scrubbing. TrueNAS puts deduplication writes at up to 25 percent faster and says encryption is faster on CPUs with AVX2, which covers all currently shipping TrueNAS Enterprise appliances. Administrators can set default user, group, and project quotas, while scrub operations can now be restricted to defined time windows. Write allocation changes are also intended to reduce fragmentation as pools fill.
Linux moves to kernel 6.18, adding updated hardware support for Broadcom tri-mode HBAs, PCIe Gen5 switching, and newer NVIDIA GPUs. LXC containers, which previously progressed through experimental support in earlier TrueNAS releases, are now fully supported.
The WebUI also receives smaller administrative changes: Alerts can now include information about resolving the reported problem, user management takes fewer clicks, and self-encrypting drives can be configured through the interface instead of requiring command-line management.
Native S3 Access with TrueNAS Object Interface
RC.1 also introduces the TrueNAS Object Interface, an early-access S3-compatible service built directly into TrueNAS. In the past, object storage usually meant running third-party software in a container. With the new interface, an S3 bucket maps directly to a ZFS dataset, so it can use the same snapshots, quotas, replication, and other ZFS features already available in TrueNAS.
The initial release supports multipart uploads, object tagging, bucket and object ACLs, versioning, and immutability. The Object Interface is available across TrueNAS editions with no capacity limits and can also run in offline, air-gapped environments, while versioning and Object Lock require TrueNAS Connect Plus or TrueNAS Enterprise. TrueNAS is targeting full production status for the feature in 2027.
TrueNAS 27 RC.1 Availability
TrueNAS 27 RC.1 is mainly for testing and early adopters. For production systems, TrueNAS recommends waiting for the final 27.0 release, which is still expected in early December 2026.
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